This paper presents an investigation on the performance degradation of circular thin-walled concrete-filled steel tubular stub columns in the high-latitude offshore region. 24 specimens were loaded axially after freeze-thaw cycles and salt spray corrosion. The results show that with the increase of corrosion rate and concrete grade, the strength degradation of the specimens after the peak point becomes severe. The increase of corrosion rate approximately linearly reduces the ultimate strength of the specimens after freeze-thaw cycles, regardless of concrete grade. The ductility index and the composite elastic modulus of the circular thin-walled CFST stubs are decreased by corrosion after freeze-thaw cycles. Two design methods are proposed based on the discussions of the test results. The simplified design method for predicting the ultimate strength is proposed and validated based on the test results. The design method in Eurocode 4 for the ultimate strength is improved, in terms of material property degradation. A full-range prediction of the strength degradation of circular thin-walled CFST stubs under freeze-thaw cycles and corrosion is conducted. It is concluded that the high strength of core concrete is beneficial for the duration ability of thin-walled CFST stub columns.

本文对高纬度近海地区圆形薄壁钢管混凝土短柱的性能下降进行了研究。冻融循环和盐雾腐蚀后，轴向加载24个样品。结果表明，随着腐蚀速率和混凝土等级的提高，试样在峰值点后的强度退化加剧。无论混凝土等级如何，冻融循环后腐蚀速率的增加近似线性地降低了试样的极限强度。冻融循环后，圆形薄壁CFST短管的延性指数和复合弹性模量会因腐蚀而降低。基于对测试结果的讨论，提出了两种设计方法。提出了简化的预测极限强度的设计方法，并根据测试结果进行了验证。就材料性能下降而言，改进了Eurocode 4中用于极限强度的设计方法。进行了圆形薄壁CFST短管在冻融循环和腐蚀作用下强度退化的全范围预测。结论是，高强度的核心混凝土有利于薄壁钢管混凝土短柱的承载能力。